Switch mode voltage converters, regulators, or power supplies may be used to provide a regulated DC output voltage from an unregulated AC or DC input voltage. A flyback type switch mode power supply (SMPS) (also referred to herein as simply a “flyback”) may regulate an output voltage based on the primary current flowing through a primary switch connected in series with a primary winding of a transformer. A drive circuit of the flyback may generate a pulse to switch-on the power switch to build up energy in the primary winding that is to be transferred to a secondary winding of the transformer. While the primary switch is switched-on, the inductance of the primary winding of the transformer may cause the level of the primary current flowing through the primary switch to increase substantially linearly. When the drive circuit determines the primary current level has reached a specific threshold, the drive circuit may cause the primary switch to switch-off and cease conducting the primary current.
During operation, so as to prevent damage to the primary switch and/or to prevent damage to a load connected to the secondary winding, a flyback may limit the primary current through the primary switch to a maximum permissible current level. The maximum permissible current level may depend on the input voltage to the flyback and the amount of load that is connected to a secondary side of the transformer. As operating conditions (e.g., input voltage and amount of primary inductance) of a flyback change, the acceptable maximum primary current level for the flyback may also change thereby causing a previously acceptable maximum primary current level to no longer be acceptable for a particular application and at a particular time.